Critical Review of Bioadsorption on Modified Cellulose and Removal of Divalent Heavy Metals (Cd, Pb, and Cu)

Abstract

Heavy metal contamination in soil and water has become a serious threat to all forms of life. Finding a sustainable remediation method is the prime concern of researchers worldwide. In this quest, cellulose has emerged as a biocompatible, biodegradable, renewable, tunable, and cost-effective bioadsorbent for heavy metal removal from polluted water. Cellulose is rich in hydroxyl groups which can be chemically modified to enhance the reactivity, binding sites, and mechanical strength. Cellulose in nano size, i.e., nanofibers and nanocrystals, offer myriad opportunities to improve the aspect ratio, surface area, pore size, and hydrophilicity for effective adsorption. In this review, chemical and physical modifications in cellulose (functional group transformations, nanocellulose, nanocomposites, hydrogels, aerogels, beads, and membranes) with respect to adsorption of divalent heavy metal ions, in particular, Pb 2+ , Cu 2+ , and Cd 2+ , have been extensively discussed. This review also examines the effect of pH, concentration, temperature, and contact time on the adsorption process. Different mechanisms for heavy metal removal such as ion exchange, electrostatic interactions, complexation, chelation, precipitation, and reduction have been discussed. Theoretical insights into the mechanisms of adsorbent−adsorbate binding are critically examined in the context of modified cellulose. The authors, in the concluding section, summarize potential research directions toward developing sustainable biosorbents.

Natural and Synthetic Polymers Modified with Acid Blue 113 for Removal of Cr3+, Zn2+ and Mn2+

“…In order to obtain a huge selectivity for metal ions (M X+ ) removal new chelate materials have been developed [ 1 , 2 ]. In this, natural and synthetic polymers have proven to be able in preconcentrating and separating M X+ [ 3 , 4 ]. Therefore, they contained functional groups that strongly interacted with M X+ establishing complex combinations.…”

Synthesis of carboxylic graphene oxide‐carboxymethyl chitosan composite and its applications toward the remediation of U6+, Pb2+, Cr6+, and Cd2+ ions from aqueous solutions

“…As these contaminants are non‐degradable, toxic, cancer‐causing agents, and difficult to remove from water, heavy toxic metal ions (HTMIs) poisoning of water has become a worldwide issue due to its harmful effects on human health. [ 2 ] Precipitation, [ 3 ] membrane filtration, [ 4 ] adsorption, [ 5 ] and ion exchange [ 6 ] are commonly used methods to remove HTMIs from aqueous solutions. Several methods for removing metal ions from water have been developed, the most appealing of which is adsorption treatment.…”

Poly(3-hydroxybutyrate) Nanocomposites with Cellulose Nanocrystals

“…Cellulose is the nature’s most abundant biopolymer and can be extracted from various sources such as plants, marine life, fungi, and bacteria [ 57 ]. Regardless of its source, the prime structural unit of cellulose is comprised of linear chains of D-glucose linked by repeating β-1,4-glycosidic bonds, followed by a 180° rotation for the next linkage [ 57 , 58 ]. Owing to its large network of intermolecular and intramolecular hydrogen bonds, cellulose is insoluble in water and most organic solvents.…”